BACILLUS MALLEI 225 



ated by cultivation at 42 to 43 C. that it no longer affects guinea 

 pigs but is still fatal for mice ; No. 2 is sufficiently virulent to kill 

 guinea pigs but not rabbits. The animal to be immunized is 

 inoculated subcutaneously on the inner side of the thigh with 

 five drops of vaccine No. 1 ; twelve days later a similar dose of 

 vaccine No. 2 is injected ; fourteen days later virulent organisms 

 can be injected without any ill results. It is estimated that in 

 about 40 per cent of all the animals vaccinated immunity dis- 

 appears within a year and that to insure permanent protection 

 revaccination would be necessary every year. Nevertheless, the 

 system has done much to diminish the mortality from the disease. 

 In France statistics show that during twelve years the mortality 

 from anthrax amongst vaccinated sheep was less than 1 per cent 

 as compared with 10 per cent in flocks not thus protected. 



A moderately protective serum has been obtained from actively 

 immunized animals, but the nature of its protection is not definitely 

 known ; it is thought to be largely due to the presence of opsonins. 

 A combination of the active and passive methods of immunization 

 has been employed with the result that a single treatment is said to 

 suffice. 



B. Sub tills. In the early days of bacteriology B. subtilis, a 

 saprophytic organism found widely distributed in nature, was 

 thought to be closely related to B. anthracis because of their 

 almost identical morphological appearance. B. subtilis, com- 

 monly known as the " hay " bacillus, may be distinguished, how- 

 ever, by its motility and by its non-pathogenicity. 



BACILLUS MALLEI 



Glanders is an infectious disease primarily of horses, mules, 

 and asses ; occasionally it is transmitted to other animals and to 

 man. Towards the end of 1882 Loeffler and Schutz demonstrated 

 conclusively the causal relationship of B. mallei to the disease 

 by isolating the organism from diseased tissues and experimentally 

 producing the characteristic symptoms by inoculating it into 

 animals. 

 Q 



